📦 添加虚拟环境和启动脚本

新增:
- backend/venv/ - Python 虚拟环境
- backend/start.sh - 启动脚本（使用虚拟环境）
- backend/requirements.txt - 依赖列表
- .gitignore - 忽略虚拟环境和缓存文件

说明:
- 每个项目使用独立虚拟环境
- 避免依赖冲突
- 启动脚本自动创建和激活虚拟环境

frontend/node_modules/@babel/helper-compilation-targets/lib/debug.js

@@ -0,0 +1,28 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.getInclusionReasons = getInclusionReasons;
+var _semver = require("semver");
+var _pretty = require("./pretty.js");
+var _utils = require("./utils.js");
+function getInclusionReasons(item, targetVersions, list) {
+  const minVersions = list[item] || {};
+  return Object.keys(targetVersions).reduce((result, env) => {
+    const minVersion = (0, _utils.getLowestImplementedVersion)(minVersions, env);
+    const targetVersion = targetVersions[env];
+    if (!minVersion) {
+      result[env] = (0, _pretty.prettifyVersion)(targetVersion);
+    } else {
+      const minIsUnreleased = (0, _utils.isUnreleasedVersion)(minVersion, env);
+      const targetIsUnreleased = (0, _utils.isUnreleasedVersion)(targetVersion, env);
+      if (!targetIsUnreleased && (minIsUnreleased || _semver.lt(targetVersion.toString(), (0, _utils.semverify)(minVersion)))) {
+        result[env] = (0, _pretty.prettifyVersion)(targetVersion);
+      }
+    }
+    return result;
+  }, {});
+}
+
+//# sourceMappingURL=debug.js.map